docs: update several URLs to point to docs.named-data.net

Change-Id: I4bab897f17e2b929675119198c9eab0309b6cc3e
diff --git a/docs/release-notes/release-notes-0.6.6.rst b/docs/release-notes/release-notes-0.6.6.rst
index 822a8d0..e01fe17 100644
--- a/docs/release-notes/release-notes-0.6.6.rst
+++ b/docs/release-notes/release-notes-0.6.6.rst
@@ -5,8 +5,8 @@
 
 .. note::
    This is the last release to support the `NDN packet format version 0.2.1
-   <https://named-data.net/doc/NDN-packet-spec/0.2.1/>`__. The next release will support
-   only the `v0.3 packet format <https://named-data.net/doc/NDN-packet-spec/0.3/>`__.
+   <https://docs.named-data.net/NDN-packet-spec/0.2.1/>`__. The next release will support
+   only the `v0.3 packet format <https://docs.named-data.net/NDN-packet-spec/0.3/>`__.
 
 New features
 ^^^^^^^^^^^^